Mark alloc_jemalloc as perma-unstable

src/doc/unstable-book/src/library-features/alloc-jemalloc.md

@@ -1,13 +0,0 @@
-# `alloc_jemalloc`
-
-The tracking issue for this feature is: [#33082]
-
-[#33082]: https://github.com/rust-lang/rust/issues/33082
-
-See also [`alloc_system`](library-features/alloc-system.html).
-
-------------------------
-
-This feature has been replaced by [the `jemallocator` crate on crates.io.][jemallocator].
-
-[jemallocator]: https://crates.io/crates/jemallocator

src/liballoc_jemalloc/lib.rs

@@ -11,9 +11,8 @@
 #![no_std]
 #![allow(unused_attributes)]
 #![unstable(feature = "alloc_jemalloc",
-            reason = "this library is unlikely to be stabilized in its current \
-                      form or name",
-            issue = "27783")]
+            reason = "implementation detail of std, does not provide any public API",
+            issue = "0")]
 #![feature(core_intrinsics)]
 #![feature(libc)]
 #![feature(linkage)]